[IMPROVEMENT] Better RU localization

[twi123]

@RocketChat/android

1. Fix missing "Done" button (now it can be localized)
2. More correct RU localization

[CLAassistant]

All committers have signed the CLA.

[luciofm]

@twi123 thanks for the PR. You need to rebase your PR against develop branch and sign the CLA

[twi123]

I've signed CLA
PR rebased to develop

[luciofm]

@twi123 can you please add the string done in english to other languages with a TODO comment, like:
<string name="dialog_button_done">Done</string> <!-- TODO Add translation -->

That way your PR will pass on our automated checks.

[luciofm]

Thanks @twi123, did a rebase and squash and merge manually. Thank you again